1 JUNE 1999
F.L.E. Chu, Z. Ozkizilcik-1999
Journal of Experimental Marine Biology and Ecology, 237(1): 1-9 (from Current Contents)
Abstract:
The acceptability of two microencapsulated diets (casein-walled complex microcapsules, CWC, and CWC containing water and lipid soluble fractions of Artemia, MCWC) by striped bass larvae, from 7 to 21 days posthatching (DPH), was tested. These two microencapsulated diets were fed to striped bass larvae exclusively (CWC or MCWC alone, 1.1 mg/larva/day) or as partial replacement of live food, Artemia nauplii (two nauplii/ml + MCWC, 1.1 mg/larva/day). Controls were unfed larvae and larvae fed with a full ration of Artemia (five nauplii/ml) or 40% ration of Artemia (two nauplii/ml). The ingestion ((number of larvae with food items in the gut divided by total number of larvae examined) X 100%) of CWC and MCWC by larvae were 42% and 75%, respectively at 7 DPH, while the ingestion in groups fed with full, or 40% ration Artemia, and fed 40% Artemia plus MCWC were nearly 100% (96%-98%). On 14 DPH, the ingestion by the larvae fed CWC and MCWC increased markedly, reaching 100%. The survival of the larvae fed solely CWC and MCWC were 44% and 54% respectively, lower than the two controls fed full or 40% ration of Artemia and the group fed MCWC + 40% Artemia. The survival of the later three groups ranged from 72 to 78%. All the unfed larvae died by 19 DPH. The larvae fed a full ration of Artemia had the highest mean wet weight and total length. Supplementing the group fed 40% ration Artemia with MCWC slightly improved the growth of the larvae compared to the non-supplemented group. At the end of the experiment, larvae in that group had significantly greater wet weight gain and total length than the non-supplemented group. The results of this study revealed that a complex-protein walled capsule is readily ingested by striped bass larvae at first feeding. Potentially, the complex-protein microencapsulated diet containing Artemia extracts can be used as partial replacement of live food. However, to achieve such a goal, study is needed to improve its nutritional quality and digestibility, in particular.
(Coll William & Mary, Sch Marine Sci, Gloucester Point,VA 23062, USA, e-mail: chu@vims.edu)